Turbocompressor



July 21, 1953 Filed May 5, 1951 3 Sheets-Sheet 1 HAN 5 KQHLMANN. GU5TAVZELLBECK.

ATTORNEY.

INVENTOR5.

July 21, 1953 H. KOHLMANN ETAL TURBOCOMPRESSOR 3 Sheets-Sheet 2 FiledMay 5, 1951 INVENTORS.

HANS KOHLMANN; GUSTAV ZELLBECK.

July 21, 1953 H. KOHLMANN ETTAL 2, 0

TURBOCOMPRESSOR Filed May 5, 1951 3 Sheets-Sheet 3 INVENTORS HANSKOHLMANN. GUSTAV ZEZLLBECK.

ATTORNEY.

Patented July 21 1953 TUR ocoMPREsson Hans Kohlmann, Esslingen' (Neckar)and'Gustav Zellbeck, Oberesslingen (Neckar) Germany, assignorsto J.Eberspacher, Esslingen (Neckar),

1 Germany Application May 5, 1951, Serial N 0. 224,724

17 Claims. 01. 230-116) The present invention relates to a radial hotgas turbine driving a compressor and forming with the latter amechanically. self-contained unit. The unit may be used for compressingair for many different purposes but particularly for charging internalcombustion-engineshaving four or six cylinders.

It is an object of the invention to provide a turbo-compressor unitsuitablefor charging an internal combustion engine having four or-six.

cylinders and whose turbine is provided with a nozzle device having twoseparated gas admission conduits and being so designed as to beconveniently inserted in axial direction and removed through the exhaustside of the turbine.

, A further object of the invention is the provision of aturbo-compressor unit having extremely small overall dimensions andweight and being so constructed as to substantially reduce manufacturingcost and simplify assembly.

Another object of the invention is to provide a turbo-compressor unithaving air-cooled bearing and support means reducing consumption oflubricating oil and in which the bearing means are not only insulated byair but also shielded against heat radiation from the 'hot turbineparts. I g p Alfur'ther object of the inventionis the provision of aturbo-compressor unit in which undesired vibration of the rotor isprevented by the provision of an additional bearing loaded tocounter-balance otherwise unbalanced forces.

:Other'objects will appear from the following description of thisinvention. The manner in which the foregoing objects are achieved isshown in the appended drawings, wherein like numerals designate likeparts throughout the several views, and in which:

Fig. l is a longitudinal'sectional viewof a turboblower unit accordingto the invention;

Fig. 2 is a cross-sectional view of the shaft of the unit shown in Fig.l, the section being taken along line 11-11 of Fig.1; r

Fig. 3 is a perspective view of the rotor of the turbine of theunitaccording to Fig. l at the moment when the last core is removedafter the rotor has been cast in a chill mould;

Fig. 4 is a, cross-sectional view of the casing .of

the turbine of the unit according to Fig. l, the

section being taken along line IV--IV of said figure;

Figure 5 is a transverse' section taken at line V.-V ofFig. 4; x Y 4Fig. 6 is a longitudinal section through a modifiedbearing arrangement;

2 r Fig. 7 is a transverse section taken at line VII--VII of Fig. 6. V

Y Referringmore particularly to Fig. l, the unit according to theinvention comprises a centrally disposed hollow bearing support member Icontaining. lubricating oil. A ball bearing is 'pro-' vided ateach endof member I, the bearings being designated by numerals l8 and 20. Theysupport a shaft 9 made in one piece with a turbine rotor to. 'Air lockchambers '4 and 4'. are provided at the left and right ends,respectively, of member I, which chambers are interconnected and containair under the same pressure. A casing 6 is disposed at the right side ofmember I for receiving a radial turbine having a stationary nozzlemember5 and the aforementioned rotor H). At the left side of member I is aradial blower having a rotor II and a spiral casing I2.

A cylindrical shaft portion l6 connects the turbine wheel or rotor IIIwith the shaft 9; the bore'or cavity of portion l6 being so dimensionedthat the transverse section. of portion I6 is not greater thanone halfof the cross-section of shaft 9 and the moment of inertia of portionI'B'is the same as that of shaft 9. The described construction reducesthe flow of heat from the turbine wheel to the shaft. v

As seen in Fig. 3, the blades l3 of the turbine wheel have a rectangulartransverse sectional configuration and extend at a right angle from therotor disc. The channels formed by the blades l3 have bottoms l4 whichform an angle with a plane at a right angle to the rotation axis of therotor, the axial inclination of the bottoms l4 beginning at the inletend of the channels and increasing progressively toward the center ofthe rotoryso that the. gas operating the turbine exhausts in axialdirection.

r The entire outlet portions l5 of the blades l3 are so bent incircumferential direction that the gas leaves the buckets in a directionassuring wheel is cast with a hollow shaft trunk l6 and connected withthe shaft 9 by pressure-buttwelding. The cavity I! in the shaft trunk I6is closed by a pressed-on'cover [9 to prevent entry 7 of hot gases intothe cavity.

A disc 3 rotating with shaft 9 is provided between bearings l8 and 20.The disc picksup oil w from the bottom of chamber or cavity 2 and throwsit in finely divided or atomized state into the upper part of thechamber wherefrom the oil enters the inside of bearings l8 and 29. Theoil is also conducted toward the outside of the bearings throughopenings 65 and 65 in member I and through chambers formed at theoutsides of said member by means of covers 34 and 34. Escape of oil fromthe spaces within covers 34 and 34 is prevented by the compressed air atthe outside of covers 3:2 and 34', which fills the previously describedspaces 4 and 4 which are supplied with compressed air from the spiralcasing l2 through conduits 38 and 39 and are closed at their outsides bycovers 36 and 37. If the rotational speed of the unit changes, thepressure changes in the air chambers 2 and 4 and alsoin'the oil chain--ber 2, and oil may enter the air chambers if the speed is reduced. Toprevent this, a longitudinal bore 39 is provided in shaft 9 which boreconnects the inlet 26 of the blower with transverse bores 29 terminatingin an annular channel or groove 32 in a sleeve 3| rotating with theshaft. See Fig. 2. Channel 32 is connected with the oil chamber 2 bymeans of bores 33. The pressure in chamber 2 is thus maintained lowerthan in the chambers 4 and 4, there being always a flow of air from theair chambers into the oil chamber and therefrom throughconduits 33, 32,29 and 39 to the outside wherefrom it is drawn into the compressor. Flowof oil through conduits 33, 32, 29 and 39 is prevented by placing theconduits 33 preferably at a right angle to the bore 29 in shaft 9 asseen in Fig. 2.

As indicated in Fig. l, a sleeve 21 rotating with shaft 9 is provided atthe left side of bearing 20, which sleeve abuts against the compressorrotor l l, the latter being pressed to the sleeve by a nut 64. A springwasher 27 is interposed between the nut and the rotor. Each end ofsleeve 21 is provided with an interior recess or groove forming annularchannels 22 and 22 which are interconnected by one or more longitudinalgrooves 23. Channel 22 is connected by radial recesses or bores 26 withthe space inside cover 34 and therefore with the oil chamber 2. The hubof the compressor wheel I i has interior grooves 25 connected withradial grooves 28 at the outer end of the hub, so that air may flow fromthe oil chamber through conduits 24, 22', 23, 22, 25, and 28 to theoutside. Simultaneous escape of oil is prevented by placing the radialgrooves 24 at other points of the circumference of shaft 9 than thegrooves 23.

The covers 3% and 36 enclosing the air chamber 4 at the compressor endof the unit and the covers 34 and 3'! enclosing the air chamber 4' atthe turbine end are made of thin sheet metal, covers 34 and 3 eachhaving a curved rim portion which is press-fitted into member I. Thedisc portions of covers 3 34', 35, and 37 adjacent to shaft 9 areadapted to hold packing rings 35.

Conduit 38 conducting compressed air from the compressor to the bearingmember I has a branch 46 conductingcooling air into a space 8 formed bycover 3? and turbine casing 6 and extending over the whole side ofmember l facing the turbine. Cover 3? is so formed relatively to aflange (ii on the turbine casing t as to produce a throttling passage 4iforcing the air coming from conduit Gil to be distributed equally in theannular space 8 and to flow radially inward toward the shaft trunk 16.From there the air fiows radially outward along the. back of the turbinewheel and. is mixed with the gas operating the turbine in the clearancebetween the turbine rotor and the turbine nozzles. The describedconstruction provides two adjacent air spaces, 4' and 8, 4|, between thehot turbine casing and the shaft bearing and an emcient heat insulationfor the latter. A third air space insulates the back of the turbinewheel from the turbine casing portion facing the bearing.

The turbine casing comprises two symmetric substantially semicircularconduits 42 disposed in a common plane and in opposite relation, asillustrated in Figs. 4 and 5. Each channel has an inlet portion 33 andthe two inlet portions are separated by a wall 46. The semicircularcrosssection of the channels diminishes gradually, resulting in atongueportion 45 of the casing which portion is diametrically opposed to wall44.

The back wall 46 of the turbine faces the bearing member l and has anopening 41 through which the turbine shaft extends. A funnelshapedflange 6! projects from wall 46 and is provided with an annular portion1 which is bolted to member I. Flange BI is thin and does not conductmuch heat. It is cooled at its outside by the surrounding air. Covermember 3'1 has an annular portion interposed between the annular portion7 and member I. The inside of flange Eil is cooled by the air flowingradially through space 4i. Opposite wall 46 is a large cylindricalportion 48 receiving the annular nozzle or guide blade member 49. Tongue45 and wall M terminate at the circumference of the nozzle or guideblade member 49.

Member 49 is provided with an even number of nozzle blades 50. Twodiametrically opposed blades each have an outwardly extending por: tion,portion 5! abutting the inner end of tongue 35 and portion 5i abuttingthe inner end of the separating wall 4%. The gas streams in the twochannels 42 are thus separated from and cannot interfere with eachother. This is of particular importance if the unit is used forsupercharging internal combustion engines. The nozzle member it is openat the right side, as seen in Figs. 1

and 5, and is closed by a cover 63 closing also the right side of thecylindrical clearance between the nozzles and the turbine wheel andhaving a cylindrical portion 63 for guiding the turbine exhaust gases.The latter are additionally guided by an exhaust conduit 52 which isconnected with the turbine casing by means of an annular membrane member53 which equalizes expansion and tension caused by heat between theexhaust conduit 52 and the turbo-compressor unit.

The radial compressor together with cover 36 is bolted to the left sideof the bearing member I. The described arrangement facilitates assemblyof the unit.

Since perfect balancing of the turbo-compressor rotor and reduction ofthe bearing clearances to zero is practically impossible, the rotor willmake a circular movement in the bearings causing additional unbalancing,particularly. at high rotational speeds, and additional stresses andoperating noise. To avoid this, a third bearing, 54, may be providedbetween bearings 18 and 20, according to the invention and illustratedin Figs. 6- and 7, which is externally so much loaded that the bearingreactions in bearings i8 and 2d are always at least equal to the forcesproduced by the residual unbalance of the rotor, which forces counteractthe bearing reaction caused by the static load of the rotor. Externalloading is effected by two compression springs 55 disposed symmetricallywith respect to the radial center port memberjfi to thecasing 61. Theother ends one-end 'of 'eachr-of the satan c on the threadedi'portion 68for securing thesupof springs 55 rest on a second support part formed bylateral extensions 51 of. a pin 69 which is longitudinally slidable andguided .in a bore of part 58, which bore extends radially of bearing 54.Part 51, 89 rests on and is forced against a block 58 in which bearing.54 is mounted; To prevent rotation of part '1, 69 about the axis of pin69 and for guidance of springs .55. studs or pins 59 having ends screwedinto part 56, 68 extend through spiral springs 55. The free ends ofstuds-59 extend through holes 69 in the extensions 51 and into recessesinmember 59 and thus not 7 only prevent rotation of member51, 69 butalso sliding of member 58 along the axis of shaft 9.

-While the preferred embodiments of this in vention are shownanddescribed, modifications other than those disclosed herein may be madewithout':departing from the spirit of the invention, and referenceistherefore made to theappended claims for a definition of the scope ofthis invention. a

What is claimed is: V

1. A turbo-compressor comprising, in'combination, a radial turbine, acasing therefor, a

radial compressor, a casing therefor, a support member disposed betweensaid turbine and said compressor and havinga side to which said tur binecasing is bolted and a side to which said compressor casing is bolted,atleast two axially.

aligned bearings borne in said support member, a shaft interconnectingsaid turbine and said compressor and extending through said bearings, acooling air chamber disposed between said support member and saidturbine, a; cooling air chamber disposed between said support member andsaid compressor, a conduit interconnecting both said chambers forequalizing the air pressure therein, said support, member having acavity containing lubricating oiland communicating with both saidbearings, said compressor having a wheel having a'hub portion, a sleeveon and rotating with said shaft and disposed between said hub portionand the one of said bearings which is next tosaid compressor, saidsleeve having an interior annular groove adjacent to.

said hub portion and an interior annular groove adjacent to saidbearing, at least one longitudinal internal groove in said sleevecommunicating with bothsaid annular grooves, radial conduits extendingfrom the annular groove which is adjacent to said bearing, to theoutside of said sleeve for conducting-air from said cavity into saidlast mentioned annular groove, and conduit means in said hub portionconnecting the annular groove, which is adjacent to said hub portion,with the suction side of said compressor for drawing air from theannular groove adjacent to said 7 bearingthrough said longitudinalgroove into the annular groove adjacent to .said hub portion and throughsaid conduit means to the outside forventilating said cavity.

. 2.. A turbo-compressor as set forthin claim 1,

said radial conduits being placed at a different 3. A turbo-compressor-as set forth in claim 1,

said shaft extending through said hub portion,

- said :conduit means in; said hub'portioncomprisinglongitudinaljgrooves adjacent to said shaft,

and conduits extending radially in said hub portion from saidlastmentioned grooves to the: outside. n

4. Aturbo-compressorcomprising, in combination, a radial turbine, acasing therefor, a radial compressor, a. casing therefor, a supportmember disposed between said turbine and said compressor'and having aside to which said turbine casingis bolted and a side to which saidcompressor casingiis bolted, at least two axially aligned: bearingsborne in said support member, ashaft interconnecting said turbine andsaid compressorand extending. through: said bearings, acboling airchamber disposed between said support member and. said turbine, acooling air chamber disposed between said support member and :saidcompressor, a conduit interconnecting both said chambers for equalizingthe air pressure therein, said. support member having a cavitycontaining lubricating oil' and communicating with both said bearings,aconduit extending from the intake side of said compressor andlongitudinally through. said shaft and ending therein, a transverseconduit in said'shaft connected with said conduit and having an intakeend at the outside of. said shaft, a sleeve on and rotating with saidshaft and covering said intake end, an annular interior groove in saidsleeve adjacent to said intake end, andra'di'al conduits in said sleeveextendingfrom said annular groove to the outside of the sleeve'forreceiving air from said cavity and conducting it into the conduitextending through said shaft.

5. A turbo-compressor according to claims, said radial conduits beingangularly displaced with respect to said transverse conduit.

. '6. A turbo-compressor comprising, in combination, .aradial turbinehaving :a casing, a radial compressor having a casing, a support memberdisposed between said turbine and said compressorand having a side towhich said turbine casingis bolted and a side to which said compressorcasing is bolted, at least two axially aligned bearings borne in saidsupport member, a shaft interconnecting said turbine and said compressorand extending through said bearings, an air lock chamber disposedbetween-said supportlmember and said turbine, an air lock chamberdisposed between said support member and said compressor, a conduitinterconnecting bothsaid chambers for equalizing the air pres--. suretherein, said support member having a cavity containing lubricating oiland communicating with both said bearings, an annular recess at eachside of said support member, a cover plate disposed at either side ofsaid support member and having a ,disc'portion axially spaced from thesupport member and having a rim portion bine havinga casing, a radialcompressor having a,casing,'-a support member disposed between :saidturbine and said compressor and having a a turbine and said compressorand extending.

acagcjaic through said bearings, a cooling air chamber-at either side ofsaid support member, one of said chambers being disposed betweensaidsupport member and said turbine and the other between said compressorand said support member, a conduit interconnecting both said chambersfor equalizing the air pressure therein, the air chamber between saidsupport member and said turbine having an outside Wall, and anadditional air chamber disposed between said outside wall and saidturbine casing, extending around said shaft, and having an annularportion of relatively great diameter and axial extension and having anannular portion of relatively small diameter adjacent to said shaft, acompressed air conduit connecting said first annular portion with saidcompressor, said additional air chamber havin an intermediate portion ofrelatively small axial extension between said annular portions, saidintermediate portion constituting a throttle passage for throttling 'theflow of air toward said shaft and affording uniform distribution of theair in said additional chamber.

8. A turbo-compressor comprising a radial turbine having a casing, aradial compressor having a casing, a support member disposed betweensaid turbine and said compressor and having a side to which said turbinecasing is bolted and a side to which said compressor casing is bolted,at least two axially aligned bearings borne in said support member, ashaft interconnecting said turbine and said compressor and extendingthrough said bearings, an air lock chamber at either side of saidsupport member, one of said chambers being-disposed between said supportmember and said turbine and the other between said compressor and saidsupport member, a conduit interconnecting both said chambers forequalizing the air pressure therein, said turbine casing comprising twodiametrically opposed substantially semicircular conduits disposedsymmetrically in the same transverse plane to the rotation axis of theturbine and having a semicircular cross-sectional configuration, aninlet portion, a separating wall therein extending radially of therotation axis of the turbine and dividing said inlet portion into twoconduits individually connected with said semicircular conduits, theflow area of the latter gradually diminishing as they extend from saidinlet portion, said casing having a tongue portion diametrically opposedto said separating wall and separating the semicircular conduitsthereat, said casing having a rear wall at the side facing said supportmember, an opening in said rear wall receiving said shaft, a flangeportion extending from said rear wall and being connected with saidsupport member, said casing having a hollow cylindrical portionextending axially from said rear wall, and an annular guide blade memberfitted'into said cylindricalportion, said separating wall and saidtongue extending inwardly as far as the circumference of said guideblade member.

9. A turbo-compressor as defined in claim 8, said flange portion beingfunnel-shaped with the small diameter end at said rear wall, the airchamber between said support member and said turbine having an outsideWall spaced from and facing said fiange portion and said rear wall andforming therewith a cooling air chamber, and a conduit connecting saidcooling air chamber for compressed air flow with said compressor.

10; A turbo-compressor as defined in claim 8, said guide blade membercomprisingan even lumber of guide blades, two of said blades beingdiametrically opposed, each of said two guide blades having an outwardextension, the extension of one guide blade ending at said separatingwall and the extension of the other guide blade ending at said tongueportion for keeping separate in said guide blade member the gas streamsreceived from said semicircular conduits.

11. A turbo-compressor comprising, in combination, a radial turbinehaving a casing, a radial compressor having a casing, a support memberdisposed between said turbine and said compressor and having a side towhich said turbine casing is bolted and a side to which said compressorcasing is bolted, at least two axially aligned bearings borne in saidsupport member, a shaft interconnecting said turbine and said compressorand extending through said bearings, an air lock chamber disposedbetween said support member and said turbine, an air lock chamberdisposed between said support member and said compressor, a conduitinterconnecting both said chambers for equalizing the air pressuretherein, an oil containing cavity disposed in said support member andcommunicating with said bearings, and conduit means in said shaft androtating therewith and communicating with said cavity for removing airtherefrom.

12. A turbo-compressor as defined in claim 11, comprising disc-shapedatomizing means extending radially from and driven by said shaft anddisposed in said cavity for atomizing the oil therein.

13. A turbo-compressor as defined in claim 11, said turbine having arotor having a radial disc portion, said disc portion having a frontsurface inclined in axial direction, the inclination in creasing towardthe center of the rotor, and sheetlike blades extending at a right anglefrom the front surface of said disc portion and radially of the rotoraxis, said blades having curved end portions, the generatrices of thecurvature of said end portions extending through the rotor axis.

14. A turb-o compressor as defined in claim 11, said turbine having arotor having a disc portion, an axial bore in the center of said discportion, and a hollow cylindrical shaft trunk extending from the centerof said disc portion toward said support member and being rigidlyconnected with said shaft and having'a greater outside diameter than thelatter, the annular cross-section of said trunk being not greater thanhalf the crosssection of the connected shaft and the moment of inertiaof said shaft trunk being therefore substantially the same as that ofsaid shaft.

15. A turbo-compressor according to claim 14, comprising a cover closingthe bore in the center of said disc portion.

16. A turbo-compressorcomprising, in combination, a radial turbinehaving a casing, a radial compressor having a casing, a support memberdisposed between said turbine and said compressor and having a side towhich said turbine casing is bolted and a side to which said compressorcasing is bolted, at least two axially aligned bearings borne in saidsupport member, a shaft interconnecting said turbine and said compressorand extending through said bearings, an air lock chamber at either sideof said support member, one of said chambers being disposed between saidsupport member and said turbine and the other between said compressorand said support mem ber, a conduit interconnecting both air chambersfor equalizing the pressure therein, a'cavity in said support membercontaining lubricating oil and communicating with each of said twobearings, a third bearing axially aligned with and interposed betweensaid two bearings, and means connected with said support member and saidthird bearing and Comprising a first support part rigidly connected withsaid support member, a second support part resting on said third bearingand being slidably connected with and guided by said first support partfor radial movement to and from said shaft, two coil springs interposedbetween said support parts and disposed symmetrically with respect to aradial center line of said third bearing, a pin connected'with one ofsaid support parts, extendin through one of said springs and slidablyinto the other support part, and a pin connected with one of saidsupport parts, extending through the other spring and slidably into theother support part. 17. A turbo-compressor comprising, in combination, aradial turbine having a casing, a radial compressor having a casing, asupport member disposed between said turbine and said compressor andhaving a side to which said turbine casing is bolted and a side to whichsaid compressor casing is bolted, at least two axially aligned bearingsborne in said support member, a shaft'int'erconnecting said turbine andsaid compressor and extending through ,said bearings, an. .air lockchamber disposedbetween said support member and said turbine, an airlock chamber disposed between said support member and said compressor, aconduit interconnecting both said chambers for equalizing the airpressure therein, said support member having a cavity containinglubricating oil and communicating with both said bearings, an annularrecess at each side of said support member, a cover plate disposed ateither side of said support member and having a disc portion axiallyspaced from the support member and having a rim portion press-fittedinto said recess, an opening in said cover plates through which saidshaft extends, said ari lock chambers having an axial side wallindividually formed by said cover plates, each of said air chambershaving a second side wall individually axially spaced from said coverplates and constituted by a cover plate having a rim portion, the rimportion of one second side wall being interposed between said supportmember and said compressor casing and the rim portion of the othersecond side wall being interposed between said support member and saidturbine casing.

HANS KOHLMANI Y. GUSTAV ZELLBECK.

References Cited in the file of this patent UNITED STATES PATENTS GreatBritain Dec. 3, 1947

